C2 SST 27SF512 Chip

Works fine as a drop-in replacement for the AT29C256. These work great with the G1, G3, F1, etc. This is the max size for a 28-pin chip. When the C1 isn't big enough, such as Ford EEC-IV applications or later-model TBI GM systems, this chip will do the trick. 90ns flash drop-in replacement for 27C512 EPROMs. Make sure your programmer supports it, there's a funky programming erase voltage required (BURN1, APU1, or PocketProgrammer2 should be fine, APS1 is not). Works fine with 1227165, 1227730, and other similar ECMs. If your car normally takes a 27C128, 27C256, or 27C512, these should work for you. Just adjust the 'Start of Device' value when programming. (For 27C128 original, set to C000 hex. For 27C256 original, set to 8000 hex.)